isdaylightsavingtime in c#

DateTime f = new DateTime(2012, 8, 1); //A date on summer 
TimeZoneInfo tzf2=TimeZoneInfo.FindSystemTimeZoneById("Central Europe Standard Time");
DateTime f2 = TimeZoneInfo.ConvertTime(f, tzf2);
var isSummer = tzf2.IsDaylightSavingTime(f2);